U.S. patent application number 13/864748 was filed with the patent office on 2014-10-23 for flow manipulating arrangement for a turbine exhaust diffuser.
This patent application is currently assigned to General Electric Company. The applicant listed for this patent is GENERAL ELECTRIC COMPANY. Invention is credited to Manjunath Bangalore Chengappa, Kamlesh Mundra, Srinivas Rao Pakkala, Antanu Sadhu, Kunal Upendra Sakekar, Moorthi Subramaniyan, Lisa Anne Wichmann.
Application Number | 20140314549 13/864748 |
Document ID | / |
Family ID | 51629039 |
Filed Date | 2014-10-23 |
United States Patent
Application |
20140314549 |
Kind Code |
A1 |
Pakkala; Srinivas Rao ; et
al. |
October 23, 2014 |
FLOW MANIPULATING ARRANGEMENT FOR A TURBINE EXHAUST DIFFUSER
Abstract
A flow manipulating arrangement for a turbine exhaust diffuser
includes a strut having a leading edge and a trailing edge, the
strut disposed within the turbine exhaust diffuser. Also included
is a plurality of rotatable guide vanes disposed in close proximity
to the strut and configured to manipulate an exhaust flow, wherein
the plurality of rotatable guide vanes is coaxially aligned and
circumferentially arranged relative to each other. Further included
is an actuator in operative communication with the plurality of
rotatable guide vanes and configured to actuate an adjustment of
the plurality of rotatable guide vanes. Yet further included is a
circumferential ring operatively coupling the plurality of
rotatable guide vanes, wherein the actuator is configured to
directly actuate rotation of one of the rotatable guide vanes, and
wherein the circumferential ring actuates rotation of the plurality
of rotatable guide vanes upon rotational actuation by the
actuator.
Inventors: |
Pakkala; Srinivas Rao;
(Chintalapudi, IN) ; Chengappa; Manjunath Bangalore;
(Bangalore, IN) ; Mundra; Kamlesh; (Clifton Park,
NY) ; Sadhu; Antanu; (Bangalore, IN) ;
Sakekar; Kunal Upendra; (Sangli, IN) ; Subramaniyan;
Moorthi; (Bangalore, IN) ; Wichmann; Lisa Anne;
(Simpsonville, SC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GENERAL ELECTRIC COMPANY |
Schenectady |
NY |
US |
|
|
Assignee: |
General Electric Company
Schenectady
NY
|
Family ID: |
51629039 |
Appl. No.: |
13/864748 |
Filed: |
April 17, 2013 |
Current U.S.
Class: |
415/148 |
Current CPC
Class: |
F01D 9/02 20130101; F01D
5/146 20130101; F01D 25/30 20130101; F01D 17/162 20130101 |
Class at
Publication: |
415/148 |
International
Class: |
F01D 9/02 20060101
F01D009/02 |
Claims
1. A flow manipulating arrangement for a turbine exhaust diffuser
comprising: a strut having a leading edge and a trailing edge, the
strut disposed within the turbine exhaust diffuser; a plurality of
rotatable guide vanes disposed in close proximity to the strut and
configured to manipulate an exhaust flow, wherein the plurality of
rotatable guide vanes is coaxially aligned and circumferentially
arranged relative to each other; an actuator in operative
communication with the plurality of rotatable guide vanes and
configured to actuate an adjustment of the plurality of rotatable
guide vanes; and a circumferential ring operatively coupling the
plurality of rotatable guide vanes, wherein the actuator is
configured to directly actuate rotation of one of the rotatable
guide vanes, and wherein the circumferential ring actuates rotation
of the plurality of rotatable guide vanes upon rotational actuation
by the actuator.
2. The flow manipulating arrangement of claim 1, wherein the
turbine exhaust diffuser is an axial diffuser comprising: an inner
barrel extending in a longitudinal direction of the turbine exhaust
diffuser; and an outer wall disposed radially outwardly of the
inner barrel, wherein the strut extends between, and is operatively
coupled to, the inner barrel and the outer wall, and wherein the
plurality of rotatable guide vanes is operatively coupled to at
least one of the inner barrel and the outer wall.
3. The flow manipulating arrangement of claim 2, further comprising
a rotatable member operatively coupled to the actuator and
extending through each of the plurality of rotatable guide vanes,
wherein the plurality of rotatable guide vane is rotatable about an
axis defined by the rotatable member.
4. The flow manipulating arrangement of claim 2, further comprising
a plurality of struts coaxially aligned and circumferentially
arranged wherein the plurality of rotatable guide vanes is disposed
in at least one of an axially upstream location and an axially
downstream location of the plurality of struts.
5. The flow manipulating arrangement of claim 1, wherein the
circumferential ring is operatively coupled to a plurality of
bearings configured to facilitate sliding of the circumferential
ring within a slot structure.
6. The flow manipulating arrangement of claim 2, wherein the
plurality of rotatable guide vanes is circumferentially adjacent
to, and axially aligned with, the strut.
7. The flow manipulating arrangement of claim 1, wherein the
plurality of rotatable guide vanes is rotatable over a range of
angular positions corresponding to a range of exhaust flow
conditions.
8. The flow manipulating arrangement of claim 7, wherein the range
of angular positions comprises a first position corresponding to a
first condition and a second position corresponding to a second
condition, wherein the first condition comprises a full speed, full
load condition and the second condition comprises a part load
condition.
9. The flow manipulating arrangement of claim 3, further comprising
a gear arrangement configured to transmit mechanical power from the
actuator to the rotatable member.
10. The flow manipulating arrangement of claim 1, wherein the
turbine exhaust diffuser is a radial diffuser comprising an inner
wall and an outer wall, wherein the strut is operatively coupled to
at least one of the inner wall and the outer wall.
11. The flow manipulating arrangement of claim 10, wherein the
plurality of rotatable guide vanes is operatively coupled to the
strut.
12. The flow manipulating arrangement of claim 10, wherein the
plurality of rotatable guide vanes is rotatable over a range of
angular positions corresponding to a range of exhaust flow
conditions.
13. The flow manipulating arrangement of claim 2, further
comprising: an outer seal arrangement disposed between the
plurality of rotatable guide vanes and the outer wall; and an inner
seal arrangement disposed between the plurality of rotatable guide
vanes and the inner barrel.
14. The flow manipulating arrangement of claim 2, wherein the
plurality of rotatable guide vanes is moveable in a radial
direction.
15. A flow manipulating arrangement for a turbine exhaust diffuser
comprising: an inner barrel extending in a longitudinal direction
of the turbine exhaust diffuser; an outer wall disposed radially
outwardly of the inner barrel; a strut extending between, and
operatively coupled to, the inner barrel and the outer wall,
wherein the strut comprises a leading edge and a trailing edge; and
at least one guide vane disposed axially upstream of the leading
edge of the strut, the at least one guide vane selectively
circumferentially displaceable relative to the strut.
16. The flow manipulating arrangement of claim 15, further
comprising a motor in operative communication with the at least one
guide vane and configured to actuate an adjustment of the at least
one guide vane.
17. The flow manipulating arrangement of claim 15, further
comprising a plurality of struts coaxially aligned and
circumferentially arranged, wherein the at least one guide vane
comprises a plurality of guide vanes coaxially aligned and
circumferentially arranged.
18. The flow manipulating arrangement of claim 17, wherein the
plurality of guide vanes are circumferentially aligned with the
plurality of struts in a first position during a first condition of
an exhaust flow and displaceable to at least one additional
position during a second condition of the exhaust flow.
19. The flow manipulating arrangement of claim 15, further
comprising a plurality of struts coaxially aligned and
circumferentially arranged, wherein the at least one guide vane
comprises a plurality of guide vanes coaxially aligned and
circumferentially arranged at an axially downstream location of the
plurality of struts.
20. A flow manipulating arrangement for a radial turbine exhaust
diffuser comprising: an inner wall; an outer wall; a strut
operatively coupled to at least one of the inner wall and the outer
wall; and at least one rotatable guide vane disposed proximate the
strut, wherein the at least one rotatable guide vane is selectively
rotatable over a range of angular positions and displaceable in at
least one of an axial direction and a radial direction.
Description
BACKGROUND OF THE INVENTION
[0001] The subject matter disclosed herein relates to turbine
systems, and more particularly to boundary layer flow control of
turbine exhaust diffuser components.
[0002] Typical turbine systems, such as gas turbine systems, for
example, include an exhaust diffuser coupled to a turbine section
of the turbine system to increase efficiency of a last stage bucket
of the turbine section. The exhaust diffuser is geometrically
configured to rapidly decrease the kinetic energy of flow and
increase static pressure recovery within the exhaust diffuser.
[0003] Commonly, the exhaust diffuser is designed for full load
operation, however, the turbine system is often operated at part
load or on a cold day. Therefore, part load performance efficiency
is sacrificed, based on the full load design. Inefficiency is due,
at least in part, to flow separation on exhaust diffuser
components, such as walls and struts, for example. Flow separation
often is caused, in part, by swirling of the flow upon exit of the
last bucket stage of the turbine section and entry into the exhaust
diffuser. The magnitude of swirl may be quantified as a "tangential
flow angle," and such an angle may be up to about 60 degrees during
part load and 20 degrees during a cold day, which leads to a higher
angle of attack on the exhaust diffuser components, such as the
struts, for example. Such a flow characteristic leads to boundary
layer growth and flow separation and eventually reduced pressure
recovery
BRIEF DESCRIPTION OF THE INVENTION
[0004] According to one aspect of the invention, a flow
manipulating arrangement for a turbine exhaust diffuser includes a
strut having a leading edge and a trailing edge, the strut disposed
within the turbine exhaust diffuser. Also included is a plurality
of rotatable guide vanes disposed in close proximity to the strut
and configured to manipulate an exhaust flow, wherein the plurality
of rotatable guide vanes is coaxially aligned and circumferentially
arranged relative to each other. Further included is an actuator in
operative communication with the plurality of rotatable guide vanes
and configured to actuate an adjustment of the plurality of
rotatable guide vanes. Yet further included is a circumferential
ring operatively coupling the plurality of rotatable guide vanes,
wherein the actuator is configured to directly actuate rotation of
one of the rotatable guide vanes, and wherein the circumferential
ring actuates rotation of the plurality of rotatable guide vanes
upon rotational actuation by the actuator.
[0005] According to another aspect of the invention, a flow
manipulating arrangement for a turbine exhaust diffuser includes an
inner barrel extending in a longitudinal direction of the turbine
exhaust diffuser. Also included is an outer wall disposed radially
outwardly of the inner barrel. Further included is a strut
extending between, and operatively coupled to, the inner barrel and
the outer wall, wherein the strut comprises a leading edge and a
trailing edge. Yet further included is at least one guide vane
disposed axially upstream of the leading edge or downstream of the
trailing edge of the strut, the at least one guide vane selectively
circumferentially displaceable relative to the strut.
[0006] According to yet another aspect of the invention, a flow
manipulating arrangement for a radial turbine exhaust diffuser
includes an inner wall. Also included is an outer wall. Further
included is a strut operatively coupled to at least one of the
inner wall and the outer wall. Yet further included is at least one
rotatable guide vane disposed proximate the strut, wherein the at
least one rotatable guide vane is selectively rotatable over a
range of angular positions and displaceable in at least one of an
axial direction and a radial direction.
[0007] These and other advantages and features will become more
apparent from the following description taken in conjunction with
the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The subject matter, which is regarded as the invention, is
particularly pointed out and distinctly claimed in the claims at
the conclusion of the specification. The foregoing and other
features, and advantages of the invention are apparent from the
following detailed description taken in conjunction with the
accompanying drawings in which:
[0009] FIG. 1 is a schematic illustration of a turbine system;
[0010] FIG. 2 is a perspective view of a flow manipulation
arrangement according to a first embodiment;
[0011] FIG. 3 is a side, schematic view of the flow manipulation
arrangement of FIG. 2;
[0012] FIG. 4 is top view of guide vanes and struts of the flow
manipulation arrangement of FIG. 2;
[0013] FIG. 5 is a top view of a plurality of guide vanes
operatively coupled;
[0014] FIG. 6 is a perspective, schematic view of the plurality of
guide vanes operatively coupled;
[0015] FIG. 7 is a perspective view of the flow manipulation
arrangement according to a second embodiment;
[0016] FIG. 8 is a front elevational view of the flow manipulation
arrangement of FIG. 7;
[0017] FIG. 9 is a top view of the flow manipulation arrangement of
FIG. 7;
[0018] FIG. 10 is a top view of the flow manipulation arrangement
according to a third embodiment illustrating guide vanes in a first
position;
[0019] FIG. 11 is a top view of the flow manipulation arrangement
of FIG. 10 illustrating guide vanes in a second position;
[0020] FIG. 12 is a schematic illustration of a control mechanism
of the flow manipulation arrangement of FIG. 10; and
[0021] FIG. 13 is a schematic illustration of the flow manipulation
arrangement according to a fourth embodiment.
[0022] The detailed description explains embodiments of the
invention, together with advantages and features, by way of example
with reference to the drawings.
DETAILED DESCRIPTION OF THE INVENTION
[0023] Referring to FIG. 1, a turbine system, such as a gas turbine
system, for example, is schematically illustrated with reference
numeral 10. The turbine system 10 includes a compressor section 12,
a combustor section 14, a turbine section 16, a shaft 18 and a fuel
nozzle 20. It is to be appreciated that one embodiment of the
turbine system 10 may include a plurality of compressors 12,
combustors 14, turbines 16, shafts 18 and fuel nozzles 20. The
compressor section 12 and the turbine section 16 are coupled by the
shaft 18. The shaft 18 may be a single shaft or a plurality of
shaft segments coupled together to form the shaft 18.
[0024] The combustor section 14 uses a combustible liquid and/or
gas fuel, such as natural gas or a hydrogen rich synthetic gas, to
run the turbine system 10. For example, fuel nozzles 20 are in
fluid communication with an air supply and a fuel supply 22. The
fuel nozzles 20 create an air-fuel mixture, and discharge the
air-fuel mixture into the combustor section 14, thereby causing a
combustion that creates a hot pressurized exhaust gas. The
combustor section 14 directs the hot pressurized gas through a
transition piece into a turbine nozzle (or "stage one nozzle"), and
other stages of buckets and nozzles causing rotation of turbine
blades within an outer casing 24 of the turbine section 16.
Subsequently, the hot pressurized gas is sent from the turbine
section 16 to an exhaust diffuser 26 that is operably coupled to a
portion of the turbine section, such as the outer casing 24, for
example.
[0025] Although illustrated and described above as a gas turbine
system, it is to be appreciated that the turbine system 10 may
alternatively be a steam turbine system. As will be described
below, various embodiment of the exhaust diffuser 26 are
contemplated, such as an axial exhaust diffuser and a radial
exhaust diffuser.
[0026] Referring now to FIGS. 2 and 3, a first embodiment of a flow
manipulating arrangement 50 is illustrated within the exhaust
diffuser 26. In the illustrated embodiment, the exhaust diffuser 26
is an axial exhaust diffuser disposed axially downstream of a last
stage of the turbine section 16. The exhaust diffuser 26 includes
an inlet 28 configured to receive an exhaust flow 30 from the
turbine section 16. An outlet 32 is disposed at a downstream
location relative to the inlet 28. Extending relatively axially
along a longitudinal direction of the exhaust diffuser 26 at least
partially between the inlet 28 and the outlet 32 is an inner barrel
34 that includes an outer surface 36. Spaced radially outwardly
from the inner barrel 34, and more specifically radially outwardly
from the outer surface 36, is an outer wall 38 having an inner
surface 40. The outer wall 38 may be arranged in a relatively
diverging configuration, such that kinetic energy of the exhaust
flow 30 is lessened subsequent to entering the inlet 28 of the
exhaust diffuser 26. More particularly, a transfer of dynamic
pressure to static pressure occurs within the exhaust diffuser 26
due to the diverging configuration of the outer wall 38. The
exhaust flow 30 flows through the area defined by the outer surface
36 of the inner barrel 34 and the inner surface 40 of the outer
wall 38.
[0027] Also disposed between the outer surface 36 of the inner
barrel 34 and the inner surface 40 of the outer wall 38 is at least
one, but typically a plurality of struts 42, with exemplary
embodiments including a number of struts ranging from four (4) to
twelve (12) struts circumferentially spaced from each other in a
coaxial alignment. The plurality of struts 42 serves to hold the
inner barrel 34 and the outer wall 38 in a fixed relationship to
one another, as well as providing bearing support. As the strut 42
is disposed within the area between the inner barrel 34 and the
outer wall 38, the exhaust flow 30 passes over the strut 42.
Therefore, the strut 42 influences the flow characteristics of the
exhaust flow 30, and hence the overall exhaust diffuser
performance. The plurality of struts 42 is shaped as or surrounded
by an airfoil, and it is to be appreciated that the precise
geometry and dimensions of the plurality of struts 42 may vary from
that illustrated, based on the application. Each of the plurality
of struts 42 includes a leading edge 44 and a trailing edge 46.
[0028] As the exhaust flow 30 exits the turbine section 16, the
last stage bucket exit tangential flow angle (FIG. 4) of the
exhaust flow 30 increases based on the diverging configuration of
the outer wall 38 of the exhaust diffuser 26, as well as various
operating conditions, thereby leading to flow separation in regions
proximate the outer surface 36 of the inner barrel 34, as well as
regions proximate the various outer surfaces of the plurality of
struts 42. To reduce the flow separation described above, the
exhaust flow 30 is manipulated by the flow manipulating arrangement
50, as described in detail below.
[0029] Referring to FIGS. 4 and 5, in conjunction with FIGS. 2 and
3, the flow manipulating arrangement 50 comprises at least one, but
typically a plurality of rotatable guide vanes 52 circumferentially
spaced from each other and coaxially aligned. As described above,
the plurality of struts 42 is disposed in an axial location, such
that the struts are coaxially aligned. The plurality of rotatable
guide vanes 52 is disposed proximate the plurality of struts 42 and
at a location axially upstream of the plurality of struts 42. The
plurality of rotatable guide vanes 52 comprises an airfoil-shaped
geometry and is operatively coupled to the inner barrel 34 and/or
the outer wall 38 for support. One or more sealing components 41
may be disposed between the plurality of rotatable guide vanes 52
and the inner barrel 34 and/or the outer wall 38 for sealing at an
interface therebetween. The plurality of rotatable guide vanes 52
each include a rotatable member 54, such as a spindle or rod,
operatively coupled thereto. In one embodiment, the rotatable
member 54 extends in a radial direction through a portion of the
plurality of rotatable guide vanes 52. The rotatable member 54 is
also operatively coupled to an actuator assembly 56 (FIG. 2)
configured to actuate rotation of the rotatable member 54. In
particular, the actuator assembly 56 may be directly coupled to the
rotatable member 54, such as via an output shaft or gear of the
actuator assembly 56, or indirectly coupled to the rotatable member
54 via a gear arrangement and/or cable arrangement, generally
referred to as 58. The actuator assembly 56 refers to various
motors, including a servo motor. Alternatively, a pneumatic
actuator may actuate adjustment of the rotatable member 54. In one
embodiment, the rotatable member 54 is coupled to the inner barrel
34 and/or outer wall 38 with a bushing or bearing arrangement
mounted to the inner barrel 34 and/or outer wall 38.
[0030] The plurality of rotatable guide vanes 52 is rotatable about
an axis defined by the rotatable member 54 over a range of angular
positions. The range of angular positions advantageously provides
numerous positions of the plurality of rotatable guide vanes 52,
thereby accounting for various flow angles of the exhaust flow 30.
Specifically, the plurality of struts 42 is aligned in a direction
to provide efficient flow characteristics of the exhaust flow 30
within the exhaust diffuser 26 at certain operating conditions,
such as a base load, or full-speed, full-load operating condition.
However, flow angles of the exhaust flow 30 differ at other
operating conditions, such as a part load operating condition, for
example. In the alternate operating conditions, efficiency is
reduced due to an increase in boundary layer formation. By rotating
the plurality of rotatable guide vanes 52 to positions
corresponding to appropriate flow manipulating positions, the
exhaust flow 30 is manipulated in what is referred to as a
"straightening" manner, which results in a desirable flow angle of
the exhaust flow 30 upon passage over the plurality of struts
42.
[0031] In one embodiment, with reference to FIGS. 5 and 6, a
circumferential segment of rotatable guide vanes 60 comprises
operatively coupled rotatable guide vanes arranged in a "ganged"
relationship. The circumferential segment of rotatable guide vanes
60 comprises two or more guide vanes operatively coupled by a
circumferential ring 62. It is contemplated that any number of a
plurality of guide vanes may form the circumferential segment of
rotatable guide vanes 60. The ganged arrangement allows the
actuator assembly 56 and the gear arrangement and/or cable
arrangement 58 to directly impart rotation of a single rotatable
member, while indirectly rotating the additional guide vanes of the
circumferential segment of rotatable guide vanes 60 via the
circumferential ring 62. The circumferential ring 62 forms a rack
and pinion arrangement with additional rotatable members to
facilitate rotation of the additional guide vanes via a toothed
gear arrangement between the circumferential ring 62 and the
additional rotatable members of each guide vane. Alternatively, or
in combination with the rack and pinion arrangement, the
circumferential ring 62 may be operative coupled to one or more
bearings 63 (FIG. 6) that facilitate sliding of the circumferential
ring 62 within a slot structure 65, thereby driving a rotational
motion of each of the rotatable guide vanes about the rotatable
member 54 of the respective rotatable guide vanes.
[0032] As described above, the plurality of rotatable guide vanes
52 is rotatable over a range of angular positions. The range of
angular positions corresponds to a range of operating conditions of
the turbine system 10, and more specifically a range of angles of
tangential flow of the exhaust flow 30. For example, a first
position corresponds to a first condition and a second position
corresponds to a second condition. The first position of the
plurality of rotatable guide vanes 52 is relatively parallel to the
plurality of struts 42 at a first condition corresponding to a
full-speed, full-load operating condition of the turbine system 10.
As the speed of the turbine system 10 is reduced to a part load
condition, such as 60% speed, for example, the plurality of
rotatable guide vanes 52 are rotated to an angle that provides
desirable manipulation of the exhaust flow 30 to straighten for
flow over the plurality of struts 42.
[0033] Referring now to FIGS. 7-9, a flow manipulation arrangement
100 according to a second embodiment is illustrated. The second
embodiment is similar in many respects to the first embodiment
described in detail above, such that duplicative description of
each component is not necessary and similar reference numerals are
employed where applicable. Additionally, the second embodiment is
employed in conjunction with an axial exhaust diffuser, such as the
exhaust diffuser 26 described in detail above. In the second
embodiment, the plurality of rotatable guide vanes 52 is disposed
circumferentially adjacent to, but coaxially aligned with the
plurality of struts 42. As shown, at least a portion of the
plurality of rotatable guide vanes 52 is disposed at substantially
the same axial location of at least a portion of the plurality of
struts 42, including the leading edge 44 and/or the trailing edge
46 of the plurality of struts 42. It is contemplated that the
rotatable guide vanes and the struts may be arranged in an
alternating arrangement in a one-to-one ratio, or alternatively
more than one rotatable guide vane may be disposed between the
struts. Additionally, as is the case with the first embodiment, one
or more sealing components 41 are disposed at an interface between
the plurality of rotatable guide vanes 52 and the inner barrel 34
and/or the outer wall 38.
[0034] Referring now to FIGS. 10-12, a flow manipulation
arrangement 200 according to a third embodiment is illustrated. The
third embodiment is employed in conjunction with an axial exhaust
diffuser, such as the exhaust diffuser 26 described in detail
above. The third embodiment includes a plurality of guide vanes 202
circumferentially spaced from each other and coaxially aligned.
Additionally, the plurality of guide vanes 202 is disposed in at
least one axial stage, which may be axially upstream and/or
downstream of the plurality of struts 42.
[0035] Each of the plurality of guide vanes 202 are aligned in a
substantially parallel alignment with the plurality of struts 42,
but each stage of guide vanes is adjustable in a circumferentially
displaceable manner. Specifically, the plurality of guide vanes 202
are "clocked" to alter their alignment with the plurality of struts
42. For example, in a first position (FIG. 10), the plurality of
guide vanes 202 is circumferentially aligned with the plurality of
struts 42 and in a second position (FIG. 11), the plurality of
guide vanes 202 is circumferentially misaligned with the plurality
of struts 42. As described above, the first position and the second
position are advantageous at different operating conditions of the
turbine system 10.
[0036] As is the case with the previous embodiments described, the
flow manipulation arrangement 200 is actuated with an actuator
arrangement 204, such as one or more motors that directly or
indirectly interact with a circumferential ring 206 that controls
the position of the plurality of guide vanes 202.
[0037] Referring now to FIG. 13, a flow manipulation arrangement
300 according to a fourth embodiment is illustrated. The fourth
embodiment is similar in many respects to the first and second
embodiments described in detail above, such that duplicative
description of each component is not necessary and similar
reference numerals are employed where applicable. However, in
contrast to the axial exhaust diffuser of the first and second
embodiments, the fourth embodiment is employed in conjunction with
a radial exhaust diffuser 302. The radial exhaust diffuser 302
comprises either a steam turbine diffuser or a gas turbine
diffuser. The radial exhaust diffuser 302 includes an inner wall
304 and an outer wall 306, with at least one strut 308 operatively
coupled to at least one of the inner wall 304 and the outer wall
306. At least one guide vane 310 is operatively coupled to the at
least one strut 308, and as is the case with the previous
embodiments comprising rotatable guide vanes, the at least one
guide vane 310 is rotatable over a range of angular positions that
corresponds to a range of exhaust flow conditions. Additionally,
the at least one guide vane 310 is selectively displaceable in the
axial direction and/or the radial direction.
[0038] While the invention has been described in detail in
connection with only a limited number of embodiments, it should be
readily understood that the invention is not limited to such
disclosed embodiments. Rather, the invention can be modified to
incorporate any number of variations, alterations, substitutions or
equivalent arrangements not heretofore described, but which are
commensurate with the spirit and scope of the invention.
Additionally, while various embodiments of the invention have been
described, it is to be understood that aspects of the invention may
include only some of the described embodiments. Accordingly, the
invention is not to be seen as limited by the foregoing
description, but is only limited by the scope of the appended
claims.
* * * * *